document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=171833>Question 171833</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Need help determining the restricted values.<BR>\n" );
document.write( "(x^2-4x-21)/(x^2+16)<BR>\n" );
document.write( "I think this is the answer.<BR>\n" );
document.write( "x^2+16=0 subtract 16 to both sides<BR>\n" );
document.write( "x^2=-16 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #126927 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=126927\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You're on the right track. I'll start where you left off.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5E2=-16 ALIGN=MIDDLE  ALT=\"x%5E2=-16\"   DISABLED_style= \"max-width:90%; height:auto;\" > Start with the given equation\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=sqrt%28-16%29 ALIGN=MIDDLE  ALT=\"x=sqrt%28-16%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=-sqrt%28-16%29 ALIGN=MIDDLE  ALT=\"x=-sqrt%28-16%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > Take the square root of both sides. (note: don't forget the plus/minus)\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Now since you CANNOT take the square root of a negative number, this means that \"x\" is not a real number. So this means that you can plug in ANY number in for \"x\" and no division of zero will occur.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "So the domain is all real numbers (ie there are no restricted values) </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );